1. Field of the Invention
The present invention relates to an apparatus and method for applying a weather seal to the lip of an opening, for example a door or window frame, of a motor vehicle.
2. Disclosure Information
It is customary to fit a seal to the lip of many openings to provide a resilient lip against which a door or other closure member seats to provide a water and draft proof closure to the opening. Typically, the seal takes the form of a strip of material having a U-, V- or other channel-shaped cross-section. The channel section is push fit onto the lip of the opening in the body or other structure within which the opening is formed. If desired, the opening can be provided with a peripheral flange onto which the channel fits and the channel can be provided with internal spring tooth members which provide a positive grip between the channel and the lip of the opening to secure the strip of material in position.
The strip of material can take a number of forms and can be made from a wide range of materials. For example, the channel member can take the form of a flexible strip of metal or plastic having a series of transverse arms bent over to form the U-shaped cross section strip member. The strip member is usually covered with a plastic or fabric outer cover which carries one or more solid or hollow beads to provide axially extending external resilient sealing members at the apex of the channel section and/or along one external side wall of the channel section.
For convenience, the term weather strip will be used herein to denote in general any flexible elongated sealing strip member having the above general structure and adapted for fitting upon a peripheral flange or lip of an opening in any structure, but preferably of a door opening in a motor vehicle. Also, the term lip will be used herein to denote the peripheral edge of the opening or the projecting flange which operatively acts as the edge of the opening. The lip or flange can surround the exterior of an article, for example a door or inspection hatch, which is fitted into an aperture, rather than around the aperture or opening into which the door or hatch is fitted.
Hitherto, such weather strips have been fitted to a door opening during the manufacture of a motor vehicle by cutting the strip to the desired length to fit around the periphery of the opening. One end of the strip is then fitted onto the lip of the opening at any suitable point and the remainder then progressively located on the lip and pushed home onto the lip until the spring grippers within the channel section engage the lip. Typically, a wooden or similar mallet is used to drive the grippers home onto the lip. However, this is a cumbersome and time consuming operation. Furthermore, problems can arise in that the opposed ends of the strip can separate as the strip is driven radially outward to seat fully home on the lip of the opening, since they are not secured to one another, and the seal therefore becomes broken at that point.
It has been proposed to mechanize the operation of fitting the weather strip to a vehicle. For example, British Patent specification No. 2,152,569A proposes a system which cuts the weather strip to the length required and secures the ends of the cut strip together to form a closed loop of material. This loop is then placed on a jig having a number of radially extensible arms which support the loop in a configuration which will fit into the opening. The jig then advances to carry the loop into register with the lip of the opening and the arms extend radially to press the loop onto the lip. However, this method requires that individual, closed loops of weather strip be made and loaded for each opening and this adds to the cost and complexity of fitting the weather strip, notably on a large scale production line.
U.S. Pat. No. 4,620,354 discloses an apparatus and method for robotically applying a length of weatherstrip to a vehicle door. The '354 patent proposes the use of a single end effector disposed on an end of a robotic arm, the end effector being adapted to cut a length of weather strip from a roll to apply the strip to the opening. It is disclosed in the '354 patent that the length of the weather strip exceed the circumferential length around the inside of the opening.
U.S. Pat. Nos. 4,715,110; 4,760,636; 4,780,958; 4,843,701; and 4,852,240, all assigned to a common assignee, disclose robotic weatherstrip installation systems having a single robotic end effector disposed on the end of a multi-axes robotic arm. The end effector includes means for gripping a closed loop of weatherstrip from a hanger, transporting the loop back to the vehicle, and using an intricate series o maneuvers to roll the weatherstrip onto the door flange through the use of a powered roller. It is also known to use such an end effector to grip a free end of an open loop of weatherstrip to install the weatherstrip to the vehicle opening.
There exists a need for a simple, rapid and effective mechanical means for fitting the weather strip during the manufacture of motor vehicles.
The present invention provides a method and apparatus by which a weather strip can be applied mechanically to a peripheral lip surrounding a vehicle opening.